


{"id":35821,"date":"2019-06-07T13:55:23","date_gmt":"2019-06-07T13:55:23","guid":{"rendered":"\/forum\/forums\/topic\/thermal-boundary-conditions\/"},"modified":"2019-06-07T13:55:23","modified_gmt":"2019-06-07T13:55:23","slug":"thermal-boundary-conditions","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/thermal-boundary-conditions\/","title":{"rendered":"Thermal Boundary Conditions"},"content":{"rendered":"<p><span style=\"color: #000000; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif; font-size: 13.3333px; background-color: #f7f7f7;\">Hi,<\/span><\/p>\n<p><\/p>\n<p><span style=\"color: #000000; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif; font-size: 13.3333px; background-color: #f7f7f7;\">I am trying to&nbsp;a 3-D case to model a transient laminar heat transfer and compare the results with experimental one. In my case,&nbsp;<\/span><span style=\"background-color: #f7f7f7; color: #000000; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif; font-size: 13.3333px;\">the bottom layer is subjected to constant heat flux 1000W (temperature at 3000K)<\/span><span style=\"background-color: #f7f7f7; color: #000000; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif; font-size: 13.3333px;\">&nbsp;while the side wall are insulated and the top is free surface.<\/span><\/p>\n<p><\/p>\n<p><span style=\"background-color: #f7f7f7; color: #000000; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif; font-size: 13.3333px;\">the experimental setup as follows:<\/span><\/p>\n<p><\/p>\n<p><span style=\"background-color: #f7f7f7; color: #000000; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif; font-size: 13.3333px;\">The tank is made of double glass sidewalls with 6mm air gap to ensure thermal insulation. The bottom of the tank is made of black anodized aluminium, the under side of the base is insulated with a<\/span><span style=\"color: #000000; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif;\"><span style=\"font-size: 13.3333px;\">&nbsp;source of heat&nbsp; of 1000-W halogen lamp (colour temperature of 3000 K).<\/span><\/span><\/p>\n<p><\/p>\n<p><span style=\"background-color: #f7f7f7; color: #000000; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif; font-size: 13.3333px;\">My questions are:<\/span><\/p>\n<p><\/p>\n<p><span style=\"background-color: #f7f7f7; color: #000000; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif; font-size: 13.3333px;\"> What type of thermal boundary condition I need to set up for&nbsp;the insulated walls? does mixed BC works in this case or I need to define a new material for the side walls with insulation properties?<\/span><\/p>\n<p><\/p>\n<p><span style=\"background-color: #f7f7f7; color: #000000; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif; font-size: 13.3333px;\">For the bottom layer I have tried either to apply constant heat flux or constant temp (not combined as in the user guide) and simulate for 200 timesteps (10 sec) but I didn&#8217;t get plumes at the bottom layer, Do I need to use a S2S radiation in this case? what are the best options to apply similar source of heat at the bottom?<\/span><\/p>\n<p><\/p>\n<p><span style=\"background-color: #f7f7f7; color: #000000; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif; font-size: 13.3333px;\">Additionally, do I need to specify&nbsp; a value for the Heat Generation Rate when specifying the temp or heat flux at the bottom layer.<\/span><\/p>\n<p><\/p>\n<p><span style=\"background-color: #f7f7f7; color: #000000; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif; font-size: 13.3333px;\">any help would be appreciated.<\/span><\/p>\n<p><\/p>\n<p>&nbsp;<\/p>\n<p><\/p>\n<p><span style=\"background-color: #f7f7f7; color: #000000; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif; font-size: 13.3333px;\">Thanks<\/span><\/p>\n<p><\/p>\n<p>&nbsp;<\/p>\n<p><\/p>\n<p><span style=\"color: #000000; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif; font-size: 13.3333px; background-color: #f7f7f7;\">&nbsp;<\/span><\/p>\n","protected":false},"template":"","class_list":["post-35821","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["7993"],"_bbp_old_topic_author_name_id":["Anonymous"],"_bbp_old_is_topic_anonymous_id":["false"],"_bbp_old_closed_status_id":["publish"],"_bbp_author_ip":[null],"_bbp_old_sticky_status_id":["normal"],"_bbp_likes_count":["0","0"],"_btv_view_count":["1614"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["35821"],"_bbp_forum_id":["27792"],"_bbp_engagement":["199","163991"],"_bbp_voice_count":["2"],"_bbp_reply_count":["3"],"_bbp_last_reply_id":["86806"],"_bbp_last_active_id":["86806"],"_bbp_last_active_time":["2019-06-11 11:02:46"]},"test":"ehkh"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/35821","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/35821\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=35821"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}